Deck 28: Quantum Mechanics and Atomic Physics

Question 1

What advantage might an electron microscope have over a light microscope?

Answer 1

Electrons can be accelerated to a speed such that they have wavelength much less than light and can "see" smaller detail.

Question 2

Discuss what makes the Schrödinger wave function so non-classical.

Answer 2

Although the wave function fully describes what can be known about a particle, it only makes probability statements. Its square determines the probability density of location.

Question 3

Compare the prediction of the Bohr theory with the Schrödinger theory of the hydrogen atom concerning the angular momentum of the ground state (similarity or difference).

Answer 3

Both theories assumed quantized angular momentum, however the Bohr theory was based on L = h/(2π) for the ground state, whereas Schrödinger's wave equation predicts ZERO angular momentum in this lowest state.

Question 4

The electron spin quantum number can take on what values?

Question 5

In the periodic table, the horizontal rows are called ________ and the vertical columns are called ________.

Question 6

What letters are commonly used to designate the subshells L = 0, 1, 2, 3, and 4?

Question 7

For an orbital quantum number of 2, the magnetic quantum number can take on what allowed values?

Question 8

Explain the allowed values of the four quantum numbers for the hydrogen atom.

Question 9

If someone were to suggest that possibly half of the galaxies in the universe are composed of antiparticles ("anti-galaxies") matter has.)

Question 10

Louis de Broglie

A) was the first to produce X-ray-like diffraction patterns of electrons passing through thin metal foil (1927).
B) developed a wave equation for matter waves (1926).
C) predicted the positron from relativistic quantum mechanics (1928).
D) set the limits on the probability of measurement accuracy (1927).
E) suggested the existence of matter waves (1924).

Question 11

C. J. Davisson & L. H. Germer

A) predicted the positron from relativistic quantum mechanics (1928).
B) set the limits on the probability of measurement accuracy (1927).
C) were first to produce diffraction patterns of electrons in crystals (1927).
D) discovered the positron using a cloud chamber (1932).
E) were first to produce X-ray-like diffraction patterns of electrons passing through thin metal foil (1927).

Question 12

As a particle travels faster, its de Broglie wavelength

A) remains constant.
B) increases.
C) decreases.
D) could increase or decrease; it depends on other factors.

Question 13

Who suggested that material particles (protons, etc.) have wave properties too?

A) Bohr
B) Planck
C) Schrodinger
D) Einstein
E) de Broglie

Question 14

The part of an electron microscope that plays the same role as the lenses do in an optical microscope is

A) the coils.
B) the deflector plates.
C) the cathode.
D) the vacuum chamber.

Question 15

Which of the following microscopes is capable of "photographing" individual atoms?

A) transmission electron microscope
B) light microscope
C) scanning electron microscope
D) scanning tunneling microscope

Question 16

The reason the wavelike nature of a moving baseball is not noticed in everyday life is that

A) its frequency is too small.
B) its energy is too small.
C) its speed is too small.
D) it doesn't have a wavelike nature.
E) its wavelength is too small.

Question 17

When a photon is scattered from an electron, there will be an increase in the photon's

A) frequency.
B) momentum.
C) speed.
D) wavelength.
E) energy.

Question 18

Erwin Schrodinger

A) discovered the positron using a cloud chamber (1932).
B) was the first to produce diffraction patterns of electrons in crystals (1927).
C) developed a wave equation for matter waves (1926).
D) suggested the existence of matter waves (1924).
E) set the limits on the probability of measurement accuracy (1927).

Question 19

The square of the wave function represents the

A) probability density for finding particle.
B) position of the particle as a function of time.
C) probability of finding the particle.
D) velocity of the particle.

Question 20

Suppose that a particle is trapped in a box. How does the spacing in energy between adjacent energy levels change as the quantum number identifying a level increases?

A) The spacing decreases.
B) The spacing increases.
C) The spacing alternately increases and decreases, depending on whether the wave function is a sine or a cosine function.
D) The spacing remains constant.

Question 21

In the periodic table of elements, members of each ________ have similar chemical properties.

A) period
B) transition
C) row
D) group

Question 22

Nuclear Magnetic Resonance, NMR, is more commonly referred to as

A) MRT.
B) NRA.
C) CT-scan.
D) MRI.
E) CAT.

Question 23

In an MRI medical imaging apparatus, the patient is subject to what kind of "radiation"?

A) X-rays
B) radio
C) alpha radiation
D) gamma rays
E) beta rays

Question 24

Which quantum number denotes a "shell" and which a "subshell"?

A) L and s
B) L and m_L
C) n and L
D) m_L and m_s
E) L and m_s

Question 25

The 4d subshell field can contain how many electrons?

A) 14
B) 4
C) 2
D) 7
E) 10

Question 26

After filling the 5s level, the next higher level to be filled is

A) 4s.
B) 6s.
C) 4d.
D) 5p.
E) 5d.

Question 27

The L = 4 orbital number admits how many "orientations" of the orbital angular momentum vector?

A) 1
B) 9
C) 8
D) 4
E) 5

Question 28

In a multielectron atom, which of the following levels is just above the 6s level?

A) 4f
B) 6p
C) 7s
D) 5p
E) 4d

Question 29

The 5d subshell can contain how many electrons when filled?

A) 14
B) 21
C) 4
D) 7
E) 10

Question 30

The third SHELL has how many sub-shells?

A) 3
B) 4
C) 2
D) 5
E) 6

Question 31

Heisenberg is especially noted for his

A) improved periodic table.
B) wave equation.
C) uncertainty principle.
D) dirigible.
E) photoelectric theory.

Question 32

Werner Heisenberg

A) predicted the positron from relativistic quantum mechanics (1928).
B) set the limits on the probability of measurement accuracy (1927).
C) developed a wave equation for matter waves (1926).
D) was the first to produce X-ray-like diffraction patterns of electrons passing through thin metal foil (1927).
E) suggested the existence of matter waves (1924).

Question 33

Heisenberg's Uncertainty Principle states that

A) we can never be sure whether a particle is a wave or a particle.
B) the charge on the electron can never be known with absolute accuracy.
C) at times an electron appears to be a particle and at other times it appears to be a photon.
D) all measurements are to some extent inaccurate, no matter how good the instrument used.
E) we cannot in principle know simultaneously the position and momentum of a particle with absolute certainty.

Question 34

Natural line broadening can be understood in terms of the

A) Schrodinger wave equation.
B) Pauli exclusion principle.
C) uncertainty principle.
D) de Broglie wave length.
E) quantum numbers.

Question 35

Paul Dirac

A) set the limits on the probability of measurement accuracy (1927).
B) suggested the existence of matter waves (1924).
C) predicted the positron from relativistic quantum mechanics (1928).
D) discovered the positron using a cloud chamber (1932).
E) developed a wave equation for matter waves (1926).

Question 36

C. D. Anderson

A) discovered the positron using a cloud chamber (1932).
B) was the first to produce diffraction patterns of electrons in crystals (1927).
C) set the limits on the probability of measurement accuracy (1927).
D) was the first to produce X-ray-like diffraction patterns of electrons passing through thin metal foil (1927).
E) predicted the positron from relativistic quantum mechanics (1928).

Question 37

A positively charged electron is

A) called a muon.
B) called a positron.
C) not found in nature.
D) called a proton.
E) called a pion.

Question 38

What is created in pair production?

A) an electron and a positron
B) a proton and an electron
C) a electron and an antiproton
D) a proton and an antiproton
E) an electron and a photon

Question 39

One reason a photon could not create an odd number of electrons and positrons is that such a process would

A) not conserve energy.
B) result in the creation of mass.
C) require photon energies that are not attainable.
D) defy the uncertainty principle.
E) not conserve charge.

Question 40

An electron is confined to a one-dimensional box of width 0.10 nm, about the size of an atom. What is its energy, in eV, in the ground state?

Question 41

If the energy of a particle in a box in the ground state is E, what is the energy in the state n = 4?

Question 42

Assume you are a particle in a box called the universe. Estimate your minimum kinetic energy. (Assume the "edge" of the box is at a distance of 20. Giga Light Years.)

Question 43

Assume a proton in a 1-dim box of width 3.0 fm is in its 1 st excited state.
(a) energy (in eV) (b) is the probability density a maximum?

Question 44

The excited state of a certain atom is 13.6 eV ± 0.10 eV.
(a) What is the average lifetime of this state?
(b) If the excited energy doubled ( 27.2 eV ± 0.10 eV) how would the lifetime be affected?

Question 45

What is the threshold energy for production of a pair of muons, each of mass 207 m_e?

Question 46

What is the momentum of a 600. nm photon?

A) 2.07 eV/c
B) 2.07 MeV/c
C) 2.07 KeV/c
D) 2.07 N-s
E) 2.07 kN-m

Question 47

A person of mass 50. kg has a wavelength of 4.42 × 10^-36 m when running. How fast is she running?

A) 3 m/s
B) 1 m/s
C) 2 m/s
D) 4 m/s
E) 5 m/s

Question 48

What is the de Broglie wavelength of a ball of mass 200. g moving with a speed of 30. m/s?

A) 1.1 × 10^-34 m
B) 2.2 × 10^-34 m
C) 6.67 × 10^-27 m
D) 4.5 × 10^-28 m
E) 6.67 × 10^-31 m

Question 49

An electron has a wavelength of 0.123 nm. What is its energy in eV?

A) 20. keV
B) 10. keV
C) 80. keV
D) 40. keV
E) 60. keV

Question 50

Assuming the Earth's orbital angular momentum is quantized, estimate its angular momentum quantum number (l).

A) 3 × 10⁴⁴.
B) 3 × 10⁴⁴
C) 3 × 10²⁴
D) 3 × 10^-34
E) 3 × 10⁷⁴

Question 51

The uncertainty in the position of a proton is 0.053 nm. What is the uncertainty in its speed?

A) 2.2 m/s
B) 0.98 km/s
C) 0.60 km/s
D) 1.2 km/s
E) 37. m/s

Question 52

A photon cannot create an electron pair unless its frequency is

A) less than 1.24 × 10²⁰ Hz.
B) greater than 1.24 × 10²⁰ Hz.
C) greater than 2.47 × 10²⁰ Hz.
D) less than 2.47 × 10²⁰ Hz.
E) infinite.

Question 53

When a positronium atom decays, it emits two photons. What are the energies of the photons?

A) 0.256 MeV and 0.256 MeV
B) 0.511 MeV and 1.022 MeV
C) 0.225 MeV and 0.285 MeV
D) 0.511 MeV and 0.511 MeV
E) 1.02 GeV and 938. MeV

Question 54

Suppose you were to try to create a proton-antiproton pair by annihilation of a very high energy photon. The proton and the anti-proton have the same masses, but opposite charges. What energy photon would be required?

A) 223. MeV
B) 0.47 GeV
C) 1.88 GeV
D) 1.022 MeV
E) 940. MeV